When checking ABI stability between two domain definitions, we first make migratable copies of them. However, we also asked for the guest CPU to be updated, even though the updated CPU is supposed to be already included in the original definitions. Moreover, if we do this on the destination host during migration, we're potentially updating the definition with according to an incompatible host CPU. While updating the CPU when checking ABI stability doesn't make any sense, it actually just worked because updating the CPU doesn't do anything for custom CPUs (only host-model CPUs are affected) and we updated both definitions in the same way. Less then a year ago commit v2.3.0-rc1~42 stopped updating the CPU in the definition we got internally and only the user supplied definition was updated. However, the same commit started updating host-model CPUs to custom CPUs which are not affected by the request to update the CPU. So it still seemed to work right, unless a user upgraded libvirt 2.2.0 to a newer version while there were some domains with host-model CPUs running on the host. Such domains couldn't be migrated with a user supplied XML since libvirt would complain: Target CPU mode custom does not match source host-model The fix is pretty straightforward, we just need to stop updating the CPU when checking ABI stability. https://bugzilla.redhat.com/show_bug.cgi?id=1463957 Signed-off-by: Jiri Denemark <jdenemar@redhat.com> Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Libvirt API for virtualization
Libvirt provides a portable, long term stable C API for managing the virtualization technologies provided by many operating systems. It includes support for QEMU, KVM, Xen, LXC, bhyve, Virtuozzo, VMware vCenter and ESX, VMware Desktop, Hyper-V, VirtualBox and the POWER Hypervisor.
For some of these hypervisors, it provides a stateful management daemon which runs on the virtualization host allowing access to the API both by non-privileged local users and remote users.
Layered packages provide bindings of the libvirt C API into other languages including Python, Perl, PHP, Go, Java, OCaml, as well as mappings into object systems such as GObject, CIM and SNMP.
Further information about the libvirt project can be found on the website:
License
The libvirt C API is distributed under the terms of GNU Lesser General
Public License, version 2.1 (or later). Some parts of the code that are
not part of the C library may have the more restrictive GNU General
Public License, version 2.1 (or later). See the files COPYING.LESSER
and COPYING
for full license terms & conditions.
Installation
Libvirt uses the GNU Autotools build system, so in general can be built and installed with the usual commands. For example, to build in a manner that is suitable for installing as root, use:
$ ./configure --prefix=/usr --sysconfdir=/etc --localstatedir=/var
$ make
$ sudo make install
While to build & install as an unprivileged user
$ ./configure --prefix=$HOME/usr
$ make
$ make install
The libvirt code relies on a large number of 3rd party libraries. These will
be detected during execution of the configure
script and a summary printed
which lists any missing (optional) dependencies.
Contributing
The libvirt project welcomes contributions in many ways. For most components the best way to contribute is to send patches to the primary development mailing list. Further guidance on this can be found on the website:
https://libvirt.org/contribute.html
Contact
The libvirt project has two primary mailing lists:
- libvirt-users@redhat.com (for user discussions)
- libvir-list@redhat.com (for development only)
Further details on contacting the project are available on the website: